The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
joo --- ^ -/
INTRODUCTION H i ..:E LBiRj.
The Agricultural Research Center at ApFpka was esta fisned pri arily
through the efforts of local nurserymen anc agriculturall leaders wo recog-
nized the need for research on problems as sdcit-t i tvcorfinfJ ij foliage
plant production. -
Orange County purchased 18 acres of land and donated it to the Univer-
sity of Florida for the site. Building funds for an office building, green-
house, and storage building were appropriated by the 1965 State Legislature.
Operating funds were appropriated by a special session of the Legislature
in 1968 as part of the special appropriation for the Institute of Food and
Agricultural Sciences. The center officially opened September 1, 1968 with
only the office building completed.
Research facilities at this center have been vastly expanded since 1968
and have been designed to closely duplicate grower conditions with plants
grown under shade cloth, fiberglass and glass. Presently there are over
40,000 sq ft of research area for plant production. The center also has over
2,000 sq ft of controlled environment rooms to test indoor growth of foliage
plants under consumer conditions.
The primary objective of this research center is to conduct research
and assist in State Extension activities on commercial ornamental horti-
cultural crops of Florida. The major industries involved are foliage plants,
cut ferns and woody plants used for cut foliage.
Seven faculty positions presently located at the Agricultural Research
Center Apopka and their area of specialization are:
1. Dr. Charles A. Conover Professor, Ornamental Horticulturist and
Center Director Administration, Soils and Nutrition.
2. Dr. Ann R. Chase Asst. Professor, Plant Pathologist Ornamental
3. Dr. Ronald A. Hamlen Assoc. Professor, Entomologist Insect and
Nematode Pests of Ornamentals.
4. Dr. Richard W. Henley Assoc. Professor, Ornamentals Extension
Specialist, Ornamental Horticulture Extension Foliage.
5. Dr. Richard J. Henny Asst. Professor, Plant Geneticist Foliage
6. Dr. Dineshwar D. Mathur Asst. Professor, Ornamental Horticulturist -
Cut Fern and Cut Foliage, Research and Extension.
7. Dr. Richard T. Poole Professor, Plant Physiologist Horticulture
and Physiology of Ornamentals.
This report summarizes active research projects. Correspondence with
research or extension faculty regarding completed.projects or extension
publications should be addressed to: Agricultural Research Center Apopka,
Rt. 3 Box 580, Apopka, FL 32703.
Telephone Number: (305)-889-4161.
ARC-Apopka Research Report RH-80-1. C. A. Conover, A. R. Chase, R. A. Hamlen,
R. W. Henley, R. J. Henny, D. D. Mathur and R. T. Poole.
HORTICULTURAL RESEARCH PROGRAMS FOLIAGE
C. A. Conover and R. T. Poole
Research in this area has as its objective the development of new or
improved methods of increasing yield and quality of foliage plants. Major
research areas include nutrition, media, photoperiod, light intensity,
temperature, growth regulators, herbicides and certain cultural changes
such as irrigation methods and frequency.
Immediate plans are to develop optimum cultural recommendations for
the major foliage plant crops. Plans also include development of new crops
and methods of changing the appearance of crops presently grown.
Purpose: Research on acclimatization was begun nearly 8 years ago to reduce
problems of leaf drop and loss in quality when foliage plants are moved
from a production environment to an interior environment.
Approach: Experiments have been conducted on controllable environmental
factors during production that may influence conversion to an interior
environment. These have included light, temperature, fertilization,
growing medium and watering. Acclimatization programs have been devel-
oped for most of the major foliage plant genera, but will continue on
a few species. Emphasis is now being placed on shipping and storage
problems associated with declines in quality. Research has recently
shown that storage periods up to 10 days do not result in reduced
quality of acclimatized plants, but can seriously reduce value of non-
Program Achievements: Results of many experiments have indicated that ac-
climatization may be accomplished by growing plants under high light
and nutrition, and then holding them under reduced light and nutritional
levels for 3 to 9 months prior to interior use, or growing them under re-
duced light on lower fertilizer regimes. The best system is to grow the
plants under proper light and nutritional levels for acclimatization, as
a higher quality product is produced in less total time, and such plants
are also easier to ship and retain quality for longer periods; thus im-
proving efficiency of production.
Purpose: Industry requests for information on growth and maintenance of
foliage plants indoors continue to increase. For this reason, the level
of research effort has been increased in an attempt to solve some of the
most pressing problems facing the interior plant industry.
Approach: Experiments conducted in this area have examined the influence of
light intensity on interior plant quality and the influence of varying
fertilizer programs. More recently, the influence of light duration and
intensity have been examined as well as the simultaneous comparison of
different light durations, intensities and fertilizer levels on growth
indoors. These experiments are all aimed at helping people growing
plants indoors maintain quality for longer periods.
Program Achievements: Influence of light intensity research has shown that
most plants need a minimum of 75 to 100 foot-candles of light for 12
hours a day to maintain quality. Under such conditions, very little
fertilizer is required, but if light levels are increased to 150 foot-
candles or more, considerable plant growth will occur and higher ferti-
lizer levels will be required. Recent research on light durations have
shown that most foliage plants maintain higher quality indoors when
they do not receive more than 12 to 18 hours of light a day, and this
cannot be offset by use of higher fertilizer levels. Thus, continuous
lighting is not desirable for foliage plants utilized indoors.
Purpose: Need for information on fertilizer sources, levels, ratios and
frequency of application for the hundreds of foliage cultivars grown
commercially has created a need for fertilization research to maximize
production of quality plants. There is also need to relate these data
to recommended soluble salts levels.
Approach: Experiments being conducted in this area include effect of nitrogen
source and nitrogen:phosphorus:potassium ratios on growth and quality of
many foliage plant types. Plants of commercial quality or better are
then subjected to simulated shipping and placed in an interior environment.
Program Achievements: Utilization of research results by growers from many
experiments conducted over the last eight years has allowed production
of higher quality crops. At present, suggested fertilizer levels for over
thirty species are listed in a research report and tissue levels for
these plants have also been published. A major effect of fertilization
research has been a reduction in amount of fertilizer used, and therefore,
a better quality product being sold to consumers. The reason this has
occurred is that reductions in soluble salts present in potting media at
time of sale for placement indoors results in increased longevity.
Conversion from a 1-1-1 ratio fertilizer to a 3-1-2 has also resulted in
fertilizer savings and improved energy efficiency.
Purpose: Development of potting media capable of producing high quality
foliage'plants without special cultural manipulations. To also determine
and categorize the physical and chemical properties of media components
and relate these to growth of quality foliage plants.
Approach: Since soil medium or substrate can greatly influence growth and
quality of foliage plants, and the combinations of medium ingredients
that will produce satisfactory foliage plants are numerous, medium studies
in combination with watering and fertilizing practices are being con-
ducted to determine if a specific medium can produce good plants under
one or several watering and fertilizing schedules. Cation exchange cap-
acity, water holding capacity, capillary and noncapillary pore space,
specific gravity and pH of various mixes and ingredients are determined
and correlated with growth characteristics. Data are also being devel-
oped on prepackaged soilless mixtures and ways to evaluate soluble salts
levels in these media.
Program Achievements: Previous research at this Center has shown that many
combinations of ingredients will produce good quality plants in a rel-
atively short time and that the well aerated mixes frequently require
more frequent irrigation than a less porous mix. However, a tight mix,
one with low pore space, produces poorest growth of foliage plants unless
extreme care is taken not to over-water. Cation exchange capacity and
water holding capacity are not frequently limiting physical character-
istics of soil for plant growth.
Purpose: Fertilizer applied with each irrigation (constant fertilization)
of foliage plants is a common commercial practice but there has been
little regard to volume of water applied, the emphasis being placed
on ppm (mg/l) of the fertilizer elements in solution. Recently, water
shortages have appeared throughout the country and certain areas of
Florida have been faced with critical water shortages. There is also
a growing concern regarding contamination of water supplies by excess
applications of fertilizers. The ideal situation would be the appli-
cation of.quantities of water and fertilizer that would result in no
loss of water or fertilizer from the plant container and that would
produce an excellent quality plant.
Approach: Pots are irrigated with sufficient water to obtain approximately
10% leaching or given a limited amount of water so that no leaching
occurs. At each irrigation, beakers are placed under the pots and
amount of leachate determined. If solution drains from the pots when
no leaching is desired, the solution is poured on the top of the pot
until it is absorbed by the soil. Volume applied was determined so
that a few non leachedpots lost water that was absorbed when reapplied.
Volume applied to pots that are to be leached was determined by using
enough water so that 10-20% leachate was obtained. A series of pots
with no plants was also irrigated to give some indication of amount of
water lost by evaporation.
Program Achievements: Leachate obtained from pots fertilized with the high
level was over twice that of the low indicating either root damage or
sufficient nutrients were absorbed by the smaller root system. Leaching
the pots increased height and plant grade. A rate of 100-44-82 mg/l N-P-K
with slight leaching appears to be best. Mhos x 10-5 and pH of
soil of pots receiving the low rate with some leaching was 24 and 5.3
respectively. Plant grade was improved when pots given low fertilizer
levels were leached but leaching was detrimental to plants irrigated with
the high level of nutrition. Results indicate that high levels of ferti-
lizer result in greater water loss and a poorer quality plant. Some
leaching is desirable, even at the low level (1X) rate of fertilization.
Purpose: Although most foliage plants are easily propagated, the proper
selection of soil medium, soil and air temperature, light intensity,
irrigation method, type and condition of cutting, growth regulators
and maintenance of pest free materials is important and necessary in
order to produce a quality plant economically.
Approach: Stock plants are being grown under varying light intensities
where they receive different quantities of fertilizer. This is a con-
tinuation of several preliminary experiments that showed % rooting was
strongly affected by light and fertilizer levels received by the stock
plants. Growth regulators are also being.applied to determine their
influence on rooting and subsequent growth of cuttings from stock plants
grown under different conditions.
Program Achievements: Improvement in percentage of plants which root and
reduction in time required for development of roots has been shown to
be influenced and greatly improved by many factors. The importance of
vigorous, healthy stock plants has been demonstrated. Cuttings from
stock grown in low light and supplied with inadequate nutrition produce
small cuttings which require longer periods to root. Several varieties
of Ficus have been produced from single eye cuttings. The cuttings will
root even though half of the leaf is removed. Growth regulators have
been shown to be beneficial for a few cuttings such as Aphelandra,
Ficus and Polyscias. Additions of small amounts of fertilizer and
dolomite have been shown to be very beneficial when incorporated into
the propagation medium. This is true for fern spores as well as cut-
tings and seeds of foliage plants. Yucca elephantipes and Dracaena
massangeana canes will root faster when the lower cm is removed immed-
iately before sticking. Age is particularly important when germinating
tropical foliage seeds. Seeds should be obtained fresh and planted as
soon as possible. Propagation time of tropical plants can be reduced
greatly when medium temperatures are maintained between 75-80F.
Purpose: Many tropical. indoor plants, besides having attractive foliage, pro-
duce showy flowers which enhance salability of the plants. There is a
need to determine methods of manipulating the environment so that these
plants can be forced into bloom throughout the year. The capability of
forcing plants into bloom whenever desired is helpful in a plant breeding
program to enable fertilization of plants by other plants that bloom at
different seasons of the year and also to reduce time between different
generations of plants.
Approach: Plants are grown under various combinations of light conditions,
of intensity and duration. While subjected to these varying light con-
ditions, plants are maintained with proper nutrition, irrigation and
Program Achievements: Aphelandra have been shown to be responsive to light
intensity, not photoperiod. Five hundred foot-candles and below will
maintain Aphelandra in a vegetative state. Aphelandra grown in an
environment of one thousand foot-candles or above will produce flowers.
Christmas cactus will bloom anytime of year if given the proper photo-
period. The plants do not need to be subjected to drought, low
temperatures or inadequate fertilization to produce a plant with many
blooms. Three weeks of short days, light from 8 a.m. to 5 p.m. will
produce some flowers, five weeks of short days will produce a Christmas
cactus with many blooms anytime of the year.
Purpose: Although most foliage plants tolerate wide extremes of temperature,
2-40C, the preferred temperature for commercial production is usually
between 20 and 350C. Temperatures in the southern part of the state
are generally acceptable and many foliage plants are grown outside.
However, in the central part of the state protection from freezing
temperatures is needed. Unfortunately, the structures required to pro-
tect plants from the cold contain a large amount of heat during the
summer. Studies are needed to determine maximum and minimum temperatures
that will produce quality plants.
Approach: Foliage plants are being grown at various maximum temperatures
during-the warm part of the year, and various minimum temperatures during
the cold season. During the winter months plants are irrigated with
water of varying temperatures and during the summer, plants are watered
with various irrigation frequencies. Energy consumption, soil tempera-
ture as well as plant growth is determined.
Program Achievements: Results from an experiment last year showed that
Aglaonema, Aphelandra and Maranta receiving water with temperatures
varying from 4-210C, did not affect plant growth or quality and that
Maranta grew better at 150C than 210C, while Aglaonema grew better
at the higher temperature and Aphelandra grew equally at both temper-
atures. Pots watered with the cold water returned to their normal
temperature of approximately 210C within 2 hours. Plants grown during
the summer grew better at a maximum of 320C but plants grown at 43C
maximum and watered 4 times weekly instead of twice were of equal
quality to plants grown at 320C maximum.
Purpose: The selection of the proper light level for foliage plant production
is very important, since it influences appearance, growth rate and
longevity of plants indoors. Level of light also influences the amount
of fertilizer required to produce good quality plants.
Approach: Numerous experiments on light (shade levels) have been conducted
to determine levels that provide best appearance, growth and acclima-
tized plants. Shade variables range between 0, 30, 47, 63 and 80 per-
cent shade and are usually combined with different fertilization and
Program Achievements: Publication of light intensity research has resulted
in adoption of recommended light intensities by a majority of the
foliage industry. Foliage plants produced under reduced light have
larger leaves with increased chlorophyll levels, more open plant appear-
ance, longer internodes and reduced stem caliper. Such plants are better
adapted to utilization indoors and sell more readily.
PLANT PATHOLOGY RESEARCH PROGRAMS
A. R. Chase
USE OF TISSUE CULTURE TECHNIQUES IN FOLIAGE PLANT PRODUCTION
Purpose: The primary purpose of this research will be to develop the tech-
niques necessary for production of known lines of pathogen-free foliage
plants. These techniques will be used in specific circumstances in
which no other techniques can be successfully used to produce pathogen-
Approach: Plantlet lines are developed through tissue culture and indexed
for known plant pathogens employing appropriate pathological methods.
Once a plant line has been thoroughly indexed, multiplication studies
are initiated to develop methods of increase and.subsequent handling of
the tissue cultures.
Program Achievements: Many of the commercially-produced Dieffenbachia types
have been indexed for all known Dieffenbachia pathogens and are being
maintained in tissue culture for horticultural evaluations to determine
acceptability for introduction into the industry. Several lines of D.
maculata 'Perfection' have been selected for final evaluations with
release tentatively scheduled in early 1980. Other plant types presently
in the indexing program are species of Aglaonema, Dracaena and Philodendron.
Initial studies have indicated antibiotics may have only limited
application in commercial plant tissue cultures. Post treatment of explant
sources to dry, cool environments for at least several weeks will aid in
obtaining contaminant free explants. Bacterial contaminants can exist
within plant tissue cultures and not exhibit growth in the medium until
later division expose the contaminant to the medium surface.'
FOLIAGE PLANT DISEASE IDENTIFICATION AND CONTROL
Purpose: Identify important pathogens of foliage plants and develop effective
and safe methods for their control.
Approach: Studies are continuing to determine the identity of pathogens
affecting foliage plants in production. Isolation into pure culture
and the later reinoculation into healthy plants are steps used to
determine pathogenicity. Undescribed diseases are numerous because of
the many plants grown, the abundance of pathogens, and the very favorable
environment for disease development. Wherever possible cultural methods
for control are investigated. Chemical control compounds, where needed,
Program Achievements: The list of new or previously undescribed diseases
increases each year. Specific information on these diseases may be
found in recent publications printed in the following journals and news-
letters: Foliage Digest, Florida Foliage Grower, Plant Disease Reporter,
Phytopathology, and the Proceedings of the Florida State Horticultural
Society. A comprehensive treatment of foliage plant diseases and their
control may be found in Vol. 12 (10), Vol. 12 (11), and Vol. 13 (3) of
the Florida Foliage Grower..
DISEASE CONTROL CHEMICALS REGISTRATION AND RE-REGISTRATION
Purpose: To provide data necessary to ensure the continued availability of
disease control compounds that are effective and non-phytotoxic in the
control of tropical foliage plant pathogens.
Approach: Tests on efficacy and potential phytotoxicity are conducted under
greenhouse conditions upon control compounds deemed critical to the
future and success of the foliage plant industry. Particular attention
is paid to develop the needed data forre-registration and label expan-
sion on the critical compounds.
Program Achievements: During the pastseveral years, numerous studies have
been conducted utilizing the following compounds: Banrot, Benlate,
Captan, Daconil, Fermate, FORE, Kocide 101, Manzate 200, Streptomycin,
Truban WP, Truban EC, and Zineb. In addition, a promising new compound,
CGA 48988, specifically for control of pythiaceous fungi has been under
test for several years and is currently going through the registration
process with a release date of 1980. 1These studies have produced data
that have allowed publication of specific concentrations and rates of
application for many of the compounds presently in use in the foliage
ENTOMOLOGY AND NEMATOLOGY RESEARCH PROGRAMS
R. A. Hamlen
FOLIAGE PLANT PRODUCTION PESTS IDENTIFICATION AND CONTROL
Purpose: Identify insect, mite, nematode and other pests in foliage pro-
duction and develop effective and safe methods for their control.
Approach: Visual and microscopic observations are made of infested plant
material and that suspected to be infested to determine the identity
of pests. Pest problems are numerous in production due to the number
of foliage plant species grown, the intensive culture and the favorable
environment for rapid pest population development. Cultural methods of
control, whenever possible, are investigated. Chemical controls including
pesticides, microbial insecticides and insect growth regulators are
evaluated if effective recommendations are lacking.
Program Achievements: The tropical foliage plant industry continues to need
important pest problems identified .including species of aphids (Myzus,
Aphis), mealybugs (Phenacoccus, Pseudococcus, Planococcus), scales and
.thrips (Echinothrips, Frankliniella, Hercinothrips, Heliothrips), while
lepidopterous larvae (Spodoptera) and whiteflies (Trialeurodes), are
potentially serious pests. Soil inhabiting pests include fungus gnats
(Bradysia), root mealybugs (Geococcus, Rhizoecus), root weevils
(Diaprepes), and nematodes (Heterodera, Meloidogyne, Pratylenchus,
Radopholus). Mites are most destructive pests with the tetranychid
'(spider mites), tarsonemid (broad and cyclamen) and tenuipalpid (false
spider) mites being the most important pests in foliage production.
Specific information on foliage pest identification and control can be
found in the Florida Cooperative Extension Service Circular 432 and the
Foliage Digest I(1)3; (4):3,8; (5):3,11; (6):6; (9):6; (10):7 and II (1):
3; (3):16; and (7):6.
NONCHEMICAL CONTROL OF SPIDER MITES IN PRODUCTION AND INDOORS
Purpose: To develop acceptable alternatives to the total chemical approach
in spider mite control on tropical foliage plants.
Approach: Spider mites, Tetranychus urticae, are a most serious pest of
tropical foliage plants and chemical controls are often inadequate,
cause phytotoxicity and when regularly used, may result in resistant
mite populations. The importance of predaceous mites (phytoseiids) as
biotic agents for control of spider mites is recognized. Twb species
of predaceous mites, Phytoseiulus macropilis and P. persimilis are under
evaluation to determine their potential for use in commercial foliage
Program Achievements: Evaluations indicate Phytoseiulus species have the
ability to effectively control spider mites infesting Dieffenbachia,
Dracaena and Brassaia under greenhouse environments. Additional re-
search concerns the timing and number of predators for release and the
integration with cultural and chemical methods. Specific information
is available in the Foliage Digest 11(3):8. Tests have been completed
on evaluating Phytoseiulus in controlling spider mites on Dieffenbachia
under interior environments and the results will be published soon.
CONTROL OF THE ROOT WEEVIL, DIAPREPES ABBREVIATUS, IN FOLIAGE PLANT PRODUCTION
Purpose:. Efforts are primarily directed toward evaluating the feasibility of
using soil-applied insecticides to prevent infestation of soil media by
newly hatched Diaprepes larvae. Methods are also being evaluated to
certify already-established, container-grown ornamental plants weevil-
free for shipment out of infested areas.
Approach: Diaprepes abbreviatus is an exotic, root weevil that was first
observed in central Florida in 1964. By 1968, a quarantine area of
approximately 2,000 hectares had been established. Since 1968 the area
under quarantine has been extended three times, and approximately 20,000
hectares are presently included. This pest poses a very serious threat to
three major industries in Florida: citrus, sugarcane and ornamentals;
especially the tropical foliage and woody plant industries. During 1978-
1979, the presence of this weevil in ornamentals caused quarantines to be
issued causing severe economic losses. Since 1975 cooperative research
has been carried out between USDA, FR, SEA and the University of Florida,
IFAS, ARC-Apopka. Due to the seriousness of this pest and the threat to
ornamentals, a research program was initiated in 1979 at this research
center to increase research efforts in ornamentals.
Program Achievements: Laboratory, greenhouse and field screening of insect-
icides against newly hatched larvae have indicated that preventative
insecticide applications appear to prevent soil infestation. However,
efforts to eradicate larger larvae from highly organic soil media have
not been totally successful, a necessary requirement to quarantine this
pest. Preliminary phytotoxicity of effective chemicals and studies to
identify subtropical and tropical plant species that would support larval
development have been completed. For additional foliage plant research
data refer to the Proceedings of the Florida State Horticultural Society
88:518, Florida Entomologist 62(4):309, Journal of Economic Entomology
72:131 and the Foliage Digest I (9):5.
INSECT, MITE, NEMATODE AND OTHER PEST CONTROL CHEMICALS REGISTRATION AND
Purpose: Provide effectiveness and plant safety data to ensure the continued
availability of pest control chemicals for use in the foliage plant
Approach: Tests on effectiveness and potential phytotoxicity are carried
out under greenhouse and shade house conditions. New experimental
compounds that show potential usage in the foliage plant industry are
included and emphasis is given to compounds of low mammalian toxicity.
Presently, efforts are to obtain data required for the registrations
and label expansion of pesticides essential in production of quality
foliage plants. Major funding of this program is from IR-4 minor use
registration programs, chemical producers and the Florida tropical
Program Achievements: Specific concentrations, application times and tech-
niques have been developed for various compounds. Data from this
program has been essential i ,registrations of diazinon, Orthene ,
Pentad,, PirimoM and Vydatbeon tropical foliage plants. Chemical
producers have petitioned for registrations of other compounds for use
on foliage plants. Specific information regarding pesticide usage and
registrations can be found in the Foliage Digest I (1):8; (2):9; (3):
14; (4):13; (9):5; (11):6; II (2):3; (10):16 and ARC-Apopka Research
COMMERCIAL FOLIAGE INTEGRATED PEST MANAGEMENT PROJECT
Purpose: To evaluate standard integrated pest management (IPM) concepts
as potentially applicable in commercial foliage production and to
then adopt into commercial practice those techniques determined to
Approach: Pests and pathogens introduced into intensive, high-value cropping
systems as employed in tropical foliage plant production under green-
house or saran shade structures often find an ideal environment for
rapid population increase. These organisms may severely limit production
with the relative importance varying among the more than 300 major
foliage plant crops grown. It is not uncommon for a diverse variety
of these plants to be grown within the same structure under an identical
cropping environment. The inability to detect and constantly monitor
pest and pathogen populations coupled with their inherent ability to
increase in number rapidly presents growers with the difficult problem
of determining when to most logically apply pesticides. This difficulty
has promoted the current practice of numerous applications of pesticides
on a preventative basis to assure continued protection. These appli-
cations are more often than not excessive, thus increasing the risk
of phytotoxicity and human exposures and increasing chemical and labor
costs. The definition of IPM is generally conceived as a combined use
of chemical, cultural, genetic and biological methods for effective,
economical pest, pathogen and weed control with minimum effect on non-
target organisms and the environment. During 1979 two trial IPM tests
were initiated at commercial foliage production sites in central and
south Florida. Conditions were established which provided constant and
accurate monitoring of pest and pathogen levels to allow applications
of specific pesticides for control of detected and potentially-destructive
populations. These programs stressed proper management which emphasized
the use of preventative cultural measures that limited pest or disease
incidence and minimized indiscriminate or unnecessary pesticide usage.
Program Achievements: Data from a preliminary evaluation with Dieffenbachia
demonstrated plants under a standard commercial production pesticide
spray schedule received 14 applications (20 chemicals). The IPM area
required 3 sprays (4 chemicals) and there were no detectable differences
in plant quality or growth. The target pest was the two-spotted spider
mite, Tetranychus urticae. The establishment of an integrated pest
management program in such a diverse and complex cropping environment,
as existing in the tropical foliage plant industry, without doubt will
be difficult and will result in programs that will be continually under
evaluation and changes provided where needed.
GENETIC RESEARCH PROGRAMS
R. J. Henny
DETERMINING BREEDING POTENTIAL OF SELECTED FOLIAGE PLANTS
Purpose: To develop new or improved cultivars of ornamental tropical foliage
Approach: Studies are conducted concerning the breeding potential of dif-
ferent genera of foliage plants. Information regarding flower structure,
pollination methods, pollen structure and storage, pollen tube growth,
and the presence of genetic incompatibilities or sterilities is collected.
Intraspecific and interspecific crosses are used as the main means of com-
bining desirable traits. The inheritance of various traits is noted and
used as a guide in planning future crosses.
Program Achievements: Several species of Dieffenbachia and Agiaone ma have
been.collected and are being grown. Seeds have been obtained from over
115 different Dieffenbachia crosses. Information concerning inheritance
of leaf and plant size and growth habit, plus leaf and petiole varie-
gation patterns in Dieffenbachia is being developed. The ability to
produce seeds from interspecific crosses of Dieffenbachia indicates the
potential for development of new plant types. Over 3500 Dieffenbachia
seedlings are currently being grown for evaluation. Embryo culture has
been used successfully to overcome germination problems with the Maranta
seeds. Studies with pollen have shown methods of storing Spathiphyllum
and Vriesea pollen safely up to 4-6 months. Attempts to produce inter-
specific Aphelandra hybrids have not been successful.
HORTICULTURAL EXTENSION PROGRAMS
R. W. Henley
The State Extension Foliage Specialist was located at the Agricultural
Research Center Apopka due to the high concentration of commercial foliage
producers in Central Florida and the close proximity to University of Florida
faculty involved with tropical foliage research.
EXTENSION FOLIAGE PROGRAM AREAS:
1. Co-edit Foliage News A monthly newsletter for County Extension Agents
2. Coordinate regional short courses for foliage plant producers and
foliage plant retailers,
3. Help County Extension Horticulturists with aspects of their programs
pertaining to foliage production or utilization.
4. Assist tropical foliage plant growers with production problems.
5. Prepare visual aids on foliage plant production and utilization for
County Extension Agents and horticultural teachers.
6. Develop miscellaneous:publications pertaining to both the commercial
foliage plant industry and amateur interests.
State Road 437
State-- 1 Rodv4 f37T m r' ; m' I
To Plymouth (4 mi) To Ocoee (5 mi)
Office-conference building and pathology-physiology laboratory
Physiology Greenhouse/Breeding Greenhouse
Pathogen-free plant production greenhouse
Plant tissue and breeding laboratories
Space frame shadehouse
fn Annn~~ /5 mi~
Ia I I
---- Ir -rr .le